A. Technical Field
The present invention relates generally to optical communication network systems, and more particularly, to the discovery of network neighbors that are not physically adjacent to each other within an optical communication system.
B. Background of the Invention
In an optical communication network system, various network elements or other network nodes are connected to each other for carrying traffic from one end to another end. There may be two types of network elements in the network namely digital nodes and optical nodes. Each of the digital nodes has Lambda (wavelength) switching capability that enables a digital node to switch lambda from one port to any other port depending on how the traffic is required to be forwarded in the network. Optical nodes on the other hand are not able to switch lambda and are merely used to transfer wavelength from one port to another after its amplification.
The location of nodes, for example digital nodes, may vary within a network. Digital nodes may be connected directly or there can be one or more optical amplifiers between them. Even when two digital nodes are not physically adjacent they may behave like virtually adjacent neighbors (referred to as “virtual digital neighbors”) in order to exchange certain kinds of information. It is an essential requirement within an optical network that these digital nodes identify their virtual neighbors when they are not physically adjacent.
Typically, network neighbors (whether digital or optical) are discovered by using a “HELLO” protocol 100 as shown in FIG. 1 and which is commonly known within the art. This protocol is responsible for establishing and maintaining neighbor relationships and ensuring bidirectional communication between all neighbors which are Digital NE 1 101, Digital NE 2 102 and Digital NE 3 103.
In this “Hello” protocol, ‘Hello’ packets are sent to all router interfaces at fixed intervals. When a router sees itself listed in its neighbor's “Hello” packet it establishes a bidirectional communication. An attempt is always made to establish adjacencies over point-to-point links so that the neighbors' topological databases may be synchronized.
However, the traffic engineering topology view of a generalized multi-protocol label-switching (“GMPLS”) network provides a data-plane connectivity view of the network, which is represented at an appropriate layer of switching/connectivity capability. The traffic engineering topology gives a view of only digital nodes and not optical amplifiers, thus it may differ from the physical topology of the network when the digital nodes are not be physically adjacent and have optical amplifiers in between. In this scenario, HELLO protocol may not be efficient enough to locate the virtual neighbors.
Therefore, there is a need for a system, apparatus and method for providing discovery of neighboring network elements that are not adjacent within the network control plane.